Historic Transistor Photo Gallery   



Transistor Size (1/4” OD X 1/2”)

Original TO-9, Later TO-5

Date Code 3K (1963 Month 11)



Plastic Bubble Pack on Reverse Side


RCA 2N404



Germanium PNP Alloy Junction

Medium Speed Switch



Computers and Digital Logic 






Black or Silver Metal



Common (High Volume Production)



The RCA introduced the 2N404 in 1957, and this device was one of the first of a series of highly successful germanium computer transistors developed by RCA throughout the late 1950s.  Dr. Adolph Blicher managed the RCA group responsible for the 2N404, building on his earlier work at the Radio Receptor company where he developed the RR156 computer transistor.  The 2N404 was soon adopted an as “industry standard” and sold in the millions, with multiple companies producing equivalent devices (Raytheon, Sylvania, Tungsol, TI, GE, General Instruments, and others).  Related transistors include the 2N269 (electrically equivalent to the 2N404, but using a different case), the 2N404A (which is a higher current/voltage version of the 2N404) and the USAF 2N404 (qualified for military use). The 1957 Lafayette Radio catalog lists the RCA 2N404 price as $5.64, which was quite expensive for the time. The 1960 Lafayette Radio Semiconductor Directory lists the 2N404 as available from multiple companies (RCA, GE, Raytheon and Sylvania) for between $2.50 and $3.00.  The 2N404 continued to be available throughout the 1960s/70s.  The 2N404 remains in use today by hobbyists and experimenters, primarily as an audio or general purpose transistor – this modern usage is a fitting tribute to a classic germanium device, introduced almost 50 years ago!      


Copyright © 2007 by Jack Ward